ABSTRACT
The complete DNA genomes of the SV40-like GBM virus (GBM1), isolated from a human glioblastoma multiforme, and of two discrete classes of GBM DNA molecules that appear following three passages in CV-1 monkey cells at low multiplicities (GBM3-H and GBM3-L), were cloned in Escherichia coli using plasmid vector pBR322. The cloned viral DNAs were characterized (i) by digestion of the chimeric plasmid DNAs with various restriction enzymes followed by comparison of their electrophoretic mobilities in agarose with that of similarly digested uncloned DNA, (ii) by hybridization of digested chimeric plasmid DNAs to 32P-labeled uncloned GBM DNA, and (iii) by electron microscopy. In restriction enzyme analysis the cloned GBM DNAs showed the same cleavage pattern as the uncloned DNAs, indicating that no major insertions or deletions were present. The electrophoretic data were confirmed by electron microscopic heteroduplex analysis.
